Table of Contents for
Cycles of Nature: An Introduction to Biological Rhythms

INTRODUCTION: Around and Around:
The Importance of Cycles 1
ONE: Seeing Cycles 3
Measuring the Tide
A Short Math Lesson
TWO: Putting Cycles on the Map 9
Found in the Crowd
A Day in the Life
Longer than a Day
THREE: What Drives Cycles? 15
The Environment's Role
Evidence Against Control by Environment
Internal Sources of Rhythms
FOUR: Discovering the Wheel: The Origin of Cycles 29
Internal Timekeeping
Tuning Internal and External Rhythms
Constancy Versus Rhythmicity
FIVE: Keeping in Step with Rhythms 43
Shifting Schedules
Finding the Rhythm Range
Detecting Disease
Treating Disease
Rhythms in Ecology
SIX: Early Adventures in Chronobiology 57
A Puzzle of Fluctuation
A Puzzle of Timing
A Puzzle of Light
Further Pursuit of Rhythms
SEVEN: Activities in Chronobiology 65
Running Hot and Cold
Heart Rate
How Time Flies
How Flies Time
Run, Rodent, Run
Tip Twining
Plant "Sleep" Movement
A Colorful Revolution
Bibliography 83